That's fabulous! Your granddaughter deserves a little tip for being such a good pool girl

The pool chart indicates you're using a PS233 test kit so your results are believable. Your CYA is fine as are your other values. You can let the FC drift down and maintain it at between 3 and 5 as long as you have no CCs.

The stuff you broom up is probably just dust and dirt which falls in the pool just like it does on furniture and floor in the house. It gets stirred up when you brush and whn you swim and mostly gets filtered out. That's why I like the filter socks so much–they pick up that brown stuff.

You don't really need algaecide but if you feel you must have it, the only one we recommend is a product that says "polyquat-60" on the label. The active ingredient name is much longer but it will have 'polyquat-60' somewhere.

It's safe to swim now.

Congratulations on a job well done!